From e5a0c649e36e0db419d04446affe2564c45cf321 Mon Sep 17 00:00:00 2001
From: Elias Schneider <login@eliasschneider.com>
Date: Tue, 16 Jul 2024 19:17:53 +0200
Subject: [PATCH] fix: store only 10 share tokens in the cookies and clear the
 expired ones

---
 backend/src/share/share.controller.ts | 38 ++++++++++++++++++++++++++-
 backend/src/share/share.service.ts    | 26 +++++++++++-------
 2 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/backend/src/share/share.controller.ts b/backend/src/share/share.controller.ts
index 230ca137..2abb9399 100644
--- a/backend/src/share/share.controller.ts
+++ b/backend/src/share/share.controller.ts
@@ -10,9 +10,11 @@ import {
   Res,
   UseGuards,
 } from "@nestjs/common";
+import { JwtService } from "@nestjs/jwt";
 import { Throttle } from "@nestjs/throttler";
 import { User } from "@prisma/client";
 import { Request, Response } from "express";
+import * as moment from "moment";
 import { GetUser } from "src/auth/decorator/getUser.decorator";
 import { AdministratorGuard } from "src/auth/guard/isAdmin.guard";
 import { JwtGuard } from "src/auth/guard/jwt.guard";
@@ -29,7 +31,10 @@ import { ShareTokenSecurity } from "./guard/shareTokenSecurity.guard";
 import { ShareService } from "./share.service";
 @Controller("shares")
 export class ShareController {
-  constructor(private shareService: ShareService) {}
+  constructor(
+    private shareService: ShareService,
+    private jwtService: JwtService,
+  ) {}
 
   @Get("all")
   @UseGuards(JwtGuard, AdministratorGuard)
@@ -121,10 +126,13 @@ export class ShareController {
   @Post(":id/token")
   async getShareToken(
     @Param("id") id: string,
+    @Req() request: Request,
     @Res({ passthrough: true }) response: Response,
     @Body() body: SharePasswordDto,
   ) {
     const token = await this.shareService.getShareToken(id, body.password);
+
+    this.clearShareTokenCookies(request, response);
     response.cookie(`share_${id}_token`, token, {
       path: "/",
       httpOnly: true,
@@ -132,4 +140,32 @@ export class ShareController {
 
     return { token };
   }
+
+  /**
+   * Keeps the 10 most recent share token cookies and deletes the rest and all expired ones
+   */
+  private clearShareTokenCookies(request: Request, response: Response) {
+    const shareTokenCookies = Object.entries(request.cookies)
+      .filter(([key]) => key.startsWith("share_") && key.endsWith("_token"))
+      .map(([key, value]) => ({
+        key,
+        payload: this.jwtService.decode(value),
+      }));
+
+    const expiredTokens = shareTokenCookies.filter(
+      (cookie) => cookie.payload.exp < moment().unix(),
+    );
+    const validTokens = shareTokenCookies.filter(
+      (cookie) => cookie.payload.exp >= moment().unix(),
+    );
+
+    expiredTokens.forEach((cookie) => response.clearCookie(cookie.key));
+
+    if (validTokens.length > 10) {
+      validTokens
+        .sort((a, b) => a.payload.exp - b.payload.exp)
+        .slice(0, -10)
+        .forEach((cookie) => response.clearCookie(cookie.key));
+    }
+  }
 }
diff --git a/backend/src/share/share.service.ts b/backend/src/share/share.service.ts
index 7489b202..ad38a9da 100644
--- a/backend/src/share/share.service.ts
+++ b/backend/src/share/share.service.ts
@@ -4,7 +4,7 @@ import {
   Injectable,
   NotFoundException,
 } from "@nestjs/common";
-import { JwtService } from "@nestjs/jwt";
+import { JwtService, JwtSignOptions } from "@nestjs/jwt";
 import { Share, User } from "@prisma/client";
 import * as archiver from "archiver";
 import * as argon from "argon2";
@@ -328,15 +328,21 @@ export class ShareService {
     const { expiration } = await this.prisma.share.findUnique({
       where: { id: shareId },
     });
-    return this.jwtService.sign(
-      {
-        shareId,
-      },
-      {
-        expiresIn: moment(expiration).diff(new Date(), "seconds") + "s",
-        secret: this.config.get("internal.jwtSecret"),
-      },
-    );
+
+    const tokenPayload = {
+      shareId,
+      iat: moment().unix(),
+    };
+
+    const tokenOptions: JwtSignOptions = {
+      secret: this.config.get("internal.jwtSecret"),
+    };
+
+    if (!moment(expiration).isSame(0)) {
+      tokenOptions.expiresIn = moment(expiration).diff(new Date(), "seconds");
+    }
+
+    return this.jwtService.sign(tokenPayload, tokenOptions);
   }
 
   async verifyShareToken(shareId: string, token: string) {